Incorrect Timing

Birdsboat

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Apr 26, 2016
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I have been having problems with bending my starter bolts and have also chipped teeth off 2 ring gears and smashed the Bendix gear on 1 starter. Before all this started to happen I had removed the inlet manifold. When it was replaced the rotor shaft must have been set incorrectly. After recently checking the timing I found when piston #1 was set to TDC the rotor was pointing to point #4 on the distributor!!! I have now repositioned the rotor to point at #1 on the distributor. Before I install my 3rd new starter and 2nd new ring gear could someone confirm that this was probably the reason for me smashing ring gears and starters? I did manage to get the motor started a couple of times so don't understand how this was possible with the timing so far out???
 

Bondo

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I found when piston #1 was set to TDC the rotor was pointing to point #4 on the distributor!!!

Ayuh,.... That'll do it, for sure,... Donno how it ran at All,....
 

alldodge

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I have been having problems with bending my starter bolts and have also chipped teeth off 2 ring gears and smashed the Bendix gear on 1 starter.

Bent bolts and broken ring gears, have you fixed this issue?
If not what motor you working on?
 
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Birdsboat

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I'm about to replace another ring gear and starter so hopefully I will fix the issue now I have set the timing correctly. I'm working on a 1989 Mercruiser 4.3L
 

Jcris

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Apr 23, 2016
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I don't quite understand how timing being 180 out could cause bent bolts on a starter. And broken teeth on a ring gear. I'm surprised it would start at all as All Dodge said. Why the intake work? I've wrenched on motors my whole life and have installed distributors many times. Sometimes it's difficult to get them in there correctly and a bit of trial and error comes into play. But at no time did that lead to damage of a starter or ring gear. There must be something else going on here. Back in the day we used to have to shim starters to get them to engage properly. No offense but are you sure this is the right starter?
 
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Bt Doctur

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hydro-lock is the primary cause next to over-advanced timing.
1,6,5,4,3,2 so it should not have been able to run, plus your on the RETARDED side of the ignition
 

Birdsboat

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I stripped the intake because at the time the carb had seized and I noticed a lot of corrosion in the intake and removed to clean up. I was also surprised it was able to run however it took a lot of crankin before it would fire and would only run for a short time. I'm sure it's the the correct starter as it's the same as the original which came off (they all have been the same) I've turned the engine over by hand with plugs out and they is no tight binding spots so everything seems fine other than finding the timing was out
I really hope this was the cause because I really don't want to fit the new starter and ring gear and damage them again!!
 

Fishermark

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After recently checking the timing I found when piston #1 was set to TDC the rotor was pointing to point #4 on the distributor!!!

At top dead center, the distributor will either be pointing at #1 or #4. (It is at TDC twice per cycle - but only firing at the top of the compression stroke). I suspect you did not have the engine at TDC on the compression, or firing stroke of #1. Sounds like you had the distributor in correctly to start with.
 

biggjimm

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Jul 15, 2015
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I've seen a few times when people had the timing way off & when the plugs fired at the wrong time it would cause the motor to kick back, like an old kick starter Harley. If it kicked back hard enough I suppose it could chip teeth on the ring gear as it smashed back against the starter drive gear?? I wouldn't think it would be enough to bend starter bolts if they were tight but stranger things have happened I guess.
Jim.
 

Birdsboat

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Using an inspection mirror, you may want to make sure the engine block at/near the starter bolt holes isn't cracked.

Does your starter have the rear brace bracket in place to help hold the starter still like seen in your parts diagram for this engine model.... Item # 3, http://www.mercruiserparts.com/bam/subassembly/31478/951/10

The motor is out of the boat so the engine block has been checked and is fine. The original starter didn't have a bracket and the starter is the log bolt staggered hole pattern not like the one in the diagram
 

Birdsboat

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Apr 26, 2016
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I’ve got it running!!! I?ve had no disengagement from the starter tat all and the starter is not deflecting at the point of firing like it was with the timing 180 out!! Thanks for everyone’s input!! Next step is to fine tune the timing with a light. Am I right to say I need to set it 8 degrees BTDC? Is there a wire I need to connect to ground to set base timing mode?
Serial No- 0C856945
 
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